Abstract: FeCrCoWNi alloy wires with different Ni contents were prepared by vacuum induction magnetic levitation melting combined with cold drawing process. The effects of Ni contents on the microstructure and mechanical properties of FeCrCoWNi alloy wires were studied by transmission electron microscopy, scanning electron microscopy, and tensile testing. The results show that with the increase of Ni content, the yield strength of the alloy wire increases from 877 MPa to 1338 MPa, the tensile strength increases from 907 MPa to 1442 MPa, and the breaking elongation increases from 1.81% to 2.45%. The fracture morphology observed by SEM shows that when Ni content reaches 6.5wt%, the strain localization instability occurs rapidly, and the alloy exhibits ductile fracture charateristics. Further TEM analysis reveals that the lamellar twin spacing decreases while the dislocation density increases with the Ni content rising. It is suggested that the solid-solution-induced twin boundary strengthening and increased dislocation density may hinder dislocation slip and dynamic recrystallization, leading to a correlation between the strength and toughness of the alloy wires and the amount of solid solution elements